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title: Tool Calls
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# Tool Calls

Advanced AI models such as OpenAI GPT-3.5 and GPT-4 have the ability to call user-defined functions through tools.
A tool has a name and a set of parameters (signature). The parameters are specified using JSON schema.

Given one or several tools, an AI model can include one or more tool calls in its response.
A tool call consists of an ID, a tool name and a set of arguments that matches the tool signature.

You can invoke your tool code with the arguments and return a result.
The result can be fed back to the AI model in the next request by attaching tool result messages to the chat.

## Provider Support

Tool calls are currently supported by the OpenAI chat API and OpenAI-chat compatible providers with tool calling models:

- OpenAI GPT-3.5 and variants
- OpenAI GPT-4 and variants
- Mistral small and large
- Fireworks FireFunction v1
